Gov. Bob McDonnell said Saturday that Virginians should continue to take Hurricane Irene seriously even though it weakened to a Category 1 storm and veered a little farther offshore as it churned toward the state's coast.

"The next 12 hours are going to be very, very bad for Virginians," McDonnell said during a late-morning news conference at the state's Emergency Operations Center.

Raw Video: Hurricane Irene Hits Va. Beach

McDonnell said that although Irene's sustained wind speed had slowed to about 85 mph, it is still expected to bring "historic amounts of rain'' to eastern Virginia. The Eastern Shore could get drenched by up to 15 inches, he said, and some localities could have tropical storm-force winds for up to 20 hours because the storm is moving relatively slowly.

The governor praised Virginians for heeding mandatory evacuation orders issued by several coastal localities. About 150,000 to 200,000 Virginians were subject to mandatory evacuations, and
thousands of others left voluntarily, McDonnell said.

In Virginia Beach, souvenir shops and other businesses along the resort strip were protected by sandbags and plywood nailed over windows. The usually bustling oceanfront was virtually abandoned as waves lashed the beach. The city had several shelters open, including one at an elementary school that housed about 100 people -- most of them homeless.

McDonnell said a storm surge of up to 5 feet was expected, bringing serious flooding to low-lying areas along the state's coast.

The Virginia Department of Transportation closed the Midtown Tunnel, which connects Norfolk and Portsmouth, because of the threat of flooding and shut down the Hampton Roads Bridge-Tunnel
because of high winds. VDOT officials said both tunnels would remain closed until after the storm passes Sunday.

In Norfolk, the Coast Guard and local authorities came to the rescue of two people whose 30-foot sailboat was being tossed by Irene's waves at the mouth of the Chesapeake Bay. A Coast Guard
official said the plan was to send a rope to the boat, but by the time rescuers assembled the apparatus to accomplish that the waves and wind had pushed the boat to shore.

About 237,000 Virginians had lost electrical power by late Saturday morning, and McDonnell said that number was expected to increase substantially.

McDonnell said authorities were concerned that Irene could produce tornadoes. Parts of eastern Virginia were under a tornado watch Saturday.

Col. Steve Flaherty, superintendent of the Virginia State Police, said a few trees toppled onto Interstate 664, but few other wind-related problems had been reported by late morning. He said
that good fortune would not last.

"The worst is yet to come,'' Flaherty said. "We have the likelihood of the tree problem just getting worse, along with the standing water and flooding.''

President Barack Obama issued an emergency declaration for Virginia early Saturday, making federal funds available to offset the state's costs of such storm preparations as shelter openings
and getting emergency personnel into position.

The Virginia National Guard had about 325 troops staged at various areas, with an additional 175 on standby if needed.

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